Part VI. Running applications on other Grid sites
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Part VI. Running applications on other Grid sites

Objectives

So far you've run jobs on one grid site, osg-edu.cs.wisc.edu which was specially prepared for this tutorial. Now we will try running on some other sites on the grid. There are a few issues to cover - some in this section and some in the next.

Finding Sites

There are a number of machines that you can probably submit to on the Open Science Grid.

Finding sites on the Open Science Grid

VORS (Virtual Organization Resource Selector) is one of the monitoring tools available on the Open Science Grid. It can be used to get a good view of the Open Science Grid. For instance, there is a map of sites in the OSGEDU VO.

You can use this to check the status of many OSG sites on this list, to find out which sites are working and which sites support the OSGEDU VO which you are part of.

Checking authentication

Use globusrun to verify that you are authorized to use a site and can authenticate to it:

$ globusrun -a -r osg-edu.cs.wisc.edu/jobmanager-fork
GRAM Authentication test successful

Testing a Site

Let's test a site, using GRAM2:

$ globus-job-run osg-edu.cs.wisc.edu /bin/date
Sun Jul 10 23:25:25 CDT 2005

Try to copy your application to the site.

Caution

You don't know where to copy the files. Is there any temporary directory available? And if so, how do you find it?

If you plan to use any of the OSG sites, and you are authorized to do so (GRAM Authentication test successful), go to the VORS page again.

Pick a site. Click on that site to get information about that site. You'll be given information for submitting GRAM2 jobs (the Gatekeeper Address) which can often also be used for file transfer.

Under that listing, the entry labelled $APP location is the APPDIR you can use to store your applications.

Running a job

Now you can:

  1. Create your workspace in the APPDIR

  2. "Stage-in" your application with globus-url-copy

  3. Execute your application

Remember to replace SITE, APPDIR and YOURUSERNAME with values that are appropriate for you.

$ globus-job-run SITE /bin/mkdir APPDIR/YOURUSERNAME
$ globus-url-copy file://`pwd`/prime gsiftp://SITE/APPDIR/YOURUSERNAME/prime
$ globus-job-run SITE /bin/chmod +x APPDIR/YOURUSERNAME/prime
$ globus-job-run SITE APPDIR/YOURUSERNAME/prime 200 2 200
NO

Putting it all together

Write a script to submit jobs to multiple sites automatically.

Perhaps your script would contain something like this:

$ ./script.pl
Usage: ./script.pl <task number>
    1 - Make dir
    2 - Copy exes
    3 - Run prime jobs
    4 - Grep output
    5 - Remove dir
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Part V. Security and Certificates on the Grid Home Part VII. Packaging a Grid Application